Science Musings Blog

Tuesday, March 03, 2009

Hang onto your hats

Heliocentricity and evolution were flash points in the enduring conflict between science and faith. Evolution by natural selection remains a sticking point for many religious people. As I have written here (and elsewhere) many times, a far more serious scientific threat to traditional religion is neurobiology. Curiously, we have so far heard little about it from people of faith or from scientists.

In a letter to the editor in the February 27 issue of Science, neuroscientist Martha Farah and theologian Nancey Murphy raise the issue explicitly in hope of an early resolution. Since a resolution will be virtually unattainable, perhaps it would have been better to let the sleeping dog lie.

Farah and Murphy write:

Most religions endorse the idea of a soul (or spirit) that is distinct from the physical body. Yet as neuroscience advances, it increasingly seems that all aspects of a person can be explained by the functioning of a material system. This first became clear in the realms of motor control and perception. Yet, models of perceptual and motor capacities such as color vision and gait do not directly threaten the idea of the soul. You can still believe in what Gilbert Ryle called "the ghost in the machine" and simply conclude that color vision and gait are features of the machine rather than the ghost.

But increasingly, brain imaging techniques show that personality, emotions, morality and even spirituality correlate with brain function.

Furthermore, pharmacologic influences on these traits, as well as the effects of localized stimulation or damage, demonstrate that the brain processes in question are not mere correlates but are the physical bases of these central aspects of our personhood. If these aspects of the person are all features of the machine, why have a ghost at all?

As all of this becomes more widely known, we can expect new tension between science and faith. Predictably, we are already hearing about "nonmaterialist neuroscience," a pseudoscientific correlate of "creation science" and "intelligent design." More sparks will fly.

Farah and Murphy plead for a reexamination of the matter/spirit, body/soul, natural/supernatural dualism that has plagued Western philosophy and theology since the early centuries of the Christian era.

To be sure, dualism is intuitively compelling. Yet science often requires us to reject otherwise plausible beliefs in the face of evidence to the contrary. A full understanding of why Earth orbits the Sun (as a consequence of the way the solar system was formed) took another century after Galileo's time to develop. It may take even longer to understand why certain material systems give rise to consciousness. In the meantime, just as Galileo's view of Earth in the heavens did not render our world any less precious or beautiful, neither does the physicalism of neuroscience detract from the value or meaning of human life.

Farah and Murphy do not explicitly mention the real sticking point, which is personal immortality. My guess is that belief in life after death will be more vigorously defended by people of faith than the idea of cosmic centrality or special creation. Galileo and Darwin were warmups. We are now embarked on the century of neuroscience. You ain't seen nothin' yet.